Communication systems, such as cellular radio telecommunication systems and others, may include system-related components and populations of mobile units. The mobile units may freely move throughout the regions covered by the communication systems. The system components include base units, repeaters, control stations, switching offices, and the like, and they are controlled by operators and providers of the communication systems. Members of the populations of mobile units may communicate with each other and perhaps with equipment coupled to the public switched telecommunications networks through the system components. The mobile units are typically controlled by customers or end users of the communication systems.
A communication system may benefit from occasional system-related communications taking place between system components and mobile units. System-related communication takes place to insure the reliable and efficient operation of the system. System-related communication is not intended to relay information to end users. Rather, system-related communication needs to take place between mobile units and system components so that the system can gain useful information, such as locations for mobile units and the like.
Mobile unit location knowledge can be beneficial for several reasons. If a system knows where a particular mobile unit is located, then the system can route calls for that mobile unit to only that location and conserve system capacity in other locations. This dramatically decreases the consumption of system resources and permits a communication system to handle many more calls than could be handled if calls were routed to all locations where a particular mobile unit might possibly reside. Furthermore, knowledge of mobile unit locations is important, since in some geopolitical jurisdictions communication operations may be prohibited by the lack of proper licensing arrangements. Moreover, rates charged to customers may vary depending upon the locations of mobile units when calls are made.
While system knowledge of mobile unit locations may be particularly beneficial, other types of system-related communications may also be valuable. For example, system reliability and operational efficiency may benefit from occasional system-related communications that reprogram mobile unit operating parameters, verify mobile unit programming, verify system integrity, and the like.
Regardless of the reason for engaging in system-related communications, determining when to engage in such communications poses a serious problem. End-users of the communication system might possibly initiate system-related communications from time to time, but this is not a desirable solution. End-user control of location information makes the communication system vulnerable to pirating of communication services, communication in unauthorized geopolitical jurisdictions, and unauthorized exploitation of rate differences between jurisdictions. Moreover, requiring end-users to initiate such communications imposes an unwanted burden on the end users and results in an unreliable solution. Some end-users will forget to initiate the system-related communications, causing the system to operate upon stale information. Other end-users will initiate system-related communications more frequently than necessary and thereby waste system resources.
System-related communications might possibly be tagged onto calls routed to and from a mobile unit. For example, during a call set-up operation the system may learn where the mobile unit is located. While this solution solves some of the problems, it is an incomplete solution. When a call is directed to a particular mobile unit, the system uses current information about the mobile unites location so that the incoming call or ringing signal can be transmitted only in the area where the mobile unit currently resides. However, this solution provides no way for the system to acquire valid mobile unit location information when a mobile unit moves a significant distance but then makes no prior outgoing call that would provide its location.
Desirably, system-related communications should take place automatically from time to time. That way the communication system's reliability and operational efficiency are not controlled by the vagaries of end-user actions. However, the problem of determining when to engage in system-related communications still remains. Desirably, such communications are not initiated by a mobile unit whenever the mobile unit powers up, because more system-related communications would take place than are needed and system resources would be wasted. Likewise, such communications should not be initiated upon some sort of timing schedule. If a timing schedule specified frequent system-related communications, more system-related communications would take place than are needed, and system resources would be wasted. If a timing schedule specified infrequent system-related communications, the system would become unreliable, because it would often operate upon stale information.